class Car:
    """一次模拟汽车的简单尝试"""
    def __init__(self,make,model,year):
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 0

    def get_descriptive_name(self):
        """传递信息"""
        long_name = f"{self.year} {self.make} {self.model}"
        return long_name.title()

    def read_odometer(self):
        """打印一条指出汽车里程的信息"""
        print(f"This car has {self.odometer_reading} miles on it")

    def update_odometer(self, miles):
        if miles > self.odometer_reading:
            self.odometer_reading = miles
        else:
            print("you can not roll back an odometer")

    def increment_odometer(self, miles):
        """car内部的值自增"""
        self.odometer_reading += miles


class Battery:
    """一次模拟电动汽车电瓶的尝试"""
    def __init__(self, battery_size=75):
        self.battery_size = battery_size

    def describe_battery(self):
        print(f"This cas has a {self.battery_size}-kwh battery")

    def get_range(self):
        """打印一条消息,指出电瓶的续航里程"""
        if self.battery_size == 75:
            range = 260
        elif self.battery_size == 100:
            range = 315

        print(f"This car can go about {range} miles on a full charge.")

    def upgrade_battery(self):
        if self.battery_size == 75:
            self.battery_size =100


class ElectricCar(Car):
    """电动汽车的独特之处"""
    def __init__(self,make,model,year):
        """初始化父类属性"""
        super().__init__(make,model,year)
        self.battery = Battery()